newbiepilot

Hi all,
I know that this has nothing to do with RC Airplanes, but, I was wondering what the signs of Carbon Fiber Fatigue, what does it look like? Is it somewhat like a plastic toy, when you bend it, it turns white, and you know the plastic is weak when it has turned white. Does Carbon Fiber look like this aswell? I have found a little whitish-yellow line on some carbon fiber. Does this mean I have a crack or are going to have a crack with continued use?
Thanks.

davidfee

Carbon (graphite, really) doesn't change color before it breaks. It's basically just black and shiny. The resin matrix it is bound in often does change color when it fractures, however, so this may be what you are seeing.

-David

newbiepilot

So does this mean a weak spot? Or is it still just as strong? Would it need repair?
Thanks.

buttuh

Can you look closely to see if the crack is in the resin or is it all the way down to the reinforcement?

newbiepilot

It looks like a little whitish yellow line it seems on the surface, I'm not sure if it's a scratch, but I can't feel any indents along the suface, it feels fairly smooth around the scratch. What would it look like if it is for certain a crack or scratch?
Thanks.

buttuh

The thicker the gel coat the easier it is to identify the type of crack you got. Try looking at it from an angle and see if you can see the crack line going deep beyond the top surface.